/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the License at the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apereo.portal.events.aggr;

import org.apereo.portal.concurrency.locking.IClusterLockService;

/** Handles aggregation of portal events */
public interface PortalEventSessionPurger {
    /**
     * Name of the lock to use with {@link IClusterLockService} to call {@link
     * #doPurgeEventSessions()}
     */
    static final String PURGE_EVENT_SESSION_LOCK_NAME =
            PortalEventSessionPurger.class.getName() + ".PURGE_EVENT_SESSION_LOCK";

    /**
     * Purges portal event sessions <br>
     * Note that this method MUST be called while the current thread & JVM owns the {@link
     * #PURGE_EVENT_SESSION_LOCK_NAME} cluster wide lock via the {@link IClusterLockService}
     *
     * @return null if purging is not attempted due to some dependency being missing
     */
    EventProcessingResult doPurgeEventSessions();
}
